Key indicating switch

ABSTRACT

The casing of a lock assembly has a slot which slidably receives and radially restrains a dielectric housing. Laterally spaced upstanding electrical contacts are mounted in the housing. A switch arm pivotally mounted in the housing carries a contact pin movable between a normal open position and a closed position wherein the laterally spaced upstanding electrical contacts are connected. An actuating lever pivotally mounted in a recess of the core has a first abutment portion which extends into the key slot and a second abutment portion which engages the switch arms. When the key is inserted, the actuating lever is pivoted and pivots the switch arm to move the contact pin to closed position.

United States Patent [1 1 Krom et al.

[75] Inventors: Lynn C. Krom, Saginaw; Thomas J. Attorney A Firm H Furman Milton, Bay City, both of Mich. [57] ABSTRACT [73] Amgnee' Generral Minors Corporahon The casing of a lock assembly has a slot which slidably Detroit, MlCh. r

receives and radially restrams a dielectric housing. [22] Filed: May 16, 1973 Laterally spaced upstanding electrical contacts are mounted in the housing. A switch arm pivotally [2]] Appl' 360747 mounted in the housing carries a contact pin movable between a normal open position and a closed position [52] U.S. Cl. 200/44, ZOO/61.66 wherein the laterally spaced upstanding electrical [51] Int. Cl. H0lh 27/00 contacts are connected. An actuating lever pivotally [58] Field of Search ZOO/61.66, 42 R, 44; mounted in a recess of the core has a first abutment 70/237, 239 portion which extends into the key slot and a second abutment portion which engages the switch arms. [56] References Cited When the key is inserted, the actuating lever is piv- UNITED STATES PATENTS oted and pivots the switch arm to move the contact 3,520,161 7 1970 Jacobi ZOO/61.66 x pm closed posmon' 2 Claims, 4 Drawing Figures kv I 1 g 1-5,, A 410 h 2h i 7 if; i a

2: w i 7 I I 4 1 I w KEY INDICATING SWITCH [in 3,801,756 Apr. 2, 1974 Primary Examiner-Herman J. Hohauser 1 KEY INDICA'TING SWITCH The invention relates to a lock cylinder having a key indicating switch assembly.

It is known to provide an ignition lock having a switch which is closed upon insertion of the key into the lock. Such a switch is typically connected to an electrical buzzer circuit to indicate the presence of the key in the lock and thereby remind the vehicle operator to remove the key from the lock when exiting the vehicle.

According to the present invention an improved key indicating switch assembly for an ignition lock is provided. The key indicating switch according to the invention includes a dielectric housing mounted in a slot of the cylindrical outer casing of the ignition lock assembly. The slot fixedly mounts the housing in the casing in the radial direction but permits longitudinal movement of the housing in the slot to permit removal and replacement of the housing and the switch components mounted therein. The housing mounts laterally spaced upstanding electrical contacts which are connected in the key reminder circuit. A contact pin is mounted on a switch arm which is in turn pivotally mounted on the housing for moving the contact pin between a normal open position and a closed position in which the pin completes the electrical connection between the laterally spaced upstanding contacts. An actuating lever for operating the switch arm is pivotally mounted in a recess of the core which extends generally parallel to the key slot. The actuating lever has a first abutment portion which extends into and partially obstructs the outer end of the key slot and a second abutment portion which is engageable with the switch arm upon pivotal movement -of the actuating lever when the key is inserted into the key slot. The contact pin is arranged relative the laterally spaced upstanding contacts so that it completes the electrical connection throughout a predetermined degree of pivotal movement of the switch arm. Thus, even though wear of the various switch components may eventually result in pivotal movementof the switch arm through a reduced arc, the contact pin will nonetheless be able to connect the laterally spaced upstanding contacts and thereby provide a built-in compensation for wear.

Accordingly, one feature of the present invention is the provision of a key reminder switch housing removably mounted in a slot of the casing of an ignition switch so as to facilitate replacement of the switch.

Another feature of the invention is the provision of a key indicating switch including a contact pin carried on a pivotal switch arm for connecting laterally spaced upstanding electrical contacts through a predetermined degree of pivotal movement of the switch arm to insure completion of the electrical circuit irrespective of wear by abrasion of the switch operating components.

These and other features, objects and advantages of the invention will become apparent upon consideration of the specification and the appended drawings in which:

FIG. 1 is a view of an ignition lock assembly according to the invention and having parts broken away and in section;

FIG. 2 is a view similar to FIG. 1 showing the key inserted and the key indicating switch in closed position;

FIG. 3 is a view taken in the direction of arrows 3--3 of FIG. 1 and FIG.'4 is a partial sectional view taken in the direction of arrows 4-4 of FIG. 2.

Referring to the drawings, the lock cylinder and key indicating switch assembly generally indicated at in cludes an outer casing 12 which is adapted to be mounted by suitable means in a fixed support, not shown. The casing 12 has a stepped bore 14 in which a core 16 is rotatable. The inner end 18 of the core 16 is connected to an ignition switch or an equivalent device to be operated. Locking means, not shown, including a conventional arrangement of tumblers and a locking bar acts between the core 16 and casing 12 to prevent rotation of the core within the outer casing until a properly bitted key 20 is inserted into a key slot 22 in the core 16.

The invention provides a key indicating switch which is closed upon insertion of the key 20 into the key slot 22. The switch includes an actuating lever 24 received in a stepped recess 26 in the core which extends generally parallel to the key slot 22. Recess 26 opens out-v wardly to the periphery of the cylindrical core 16 and defines a pair of abutments 28 and 30 of the cote 16 which mount the actuating lever 24 for pivotal movement within the core 16. A spring 34 is mounted on an integral pin 36 of the core 16 and urges the actuating lever 24 to its rest position of FIG. 1 wherein the actuating lever 24 engages a stop surface 38 of the core 16. When the actuating lever is in this rest position, a laterally extending abutment portion of the actuating lever 24, as best seen in FIG. 3, extends into and partially obstructs the outer end of the key slot 22 of the casing 16.

As shown in FIG. 2, when the key 2 is inserted into the slot 22 of the core 16, the abutment portion 40 of the actuating lever is engaged by the key 20, thus pivoting lever 24 about the pivots established by the abutments 28 and 30. A laterally extending curved abutment portion 42, FIG. 4, of the actuating lever 24 operates the key indicating switch.

- The key indicating switch is mounted in a housing 44 which is constructed of a dielectric material such as plastic and is received in a longitudinally extending slot 46 of the casing 12 as best seen in FIG. 4. Slot-46 has converging walls 48 and 50 which extend generally radially of the casing and undercut shoulders 52 and 54 which engage complementary mating walls and ribs of the housing 44 so as to retain the housing 44 in the casing 12 in the radial direction but permit longitudinal movement thereof as will be discussed hereinafter. The switch includes laterally spaced upstanding contacts 56 and 58 mounted in the housing 44 as best seen in FIG. 4. Contact 58 has an integralconnector clip 60 as seen in FIGS. 1 and 2 to facilitate connection to a key reminder signal or other electrical circuit. Contact 56 has a like connector clip, not shown.

The electrical connection between the laterally spaced contacts 56 and 58 is completed by a contact pin 62. The contact pin 62 is mounted on a switch arm 64 having laterally projecting integral pivot shafts 66 which are respectively snapped into keyhole shaped slots of walls 48 and 50 of housing 44 to mount the switch arm 64 for pivotal movement between a normal open position of FIG. 1 and a closed position of FIG. 2. A coil compression spring 84 acts between housing 44 and switch arm 64 to bias the switch arm 64 to the normal open position of FIG. 1. As seen in FIG. 2, when the actuating lever 24 is pivoted by the key 20, its curved abutment portion 42 engages the switch actuating arm 64 causing it to pivot about its shaft 66 to the closed position of FIG. 2. The contact pin 62 is thus moved into engagement with the, laterally spaced contacts 56 and'58 to complete the electrical circuit. It will be noted that when the core 16 is rotated, the curved abutment portion 42 will remain in contact with the switch arm 64 at least through a predetermined degree of rotation to maintain the switch in closed position.

It will be apparent that as the lock cylinder key indicating switch assembly is used over a period of time, the surfaces of the abutment portions 40 and 42 of the actuating lever 24 and the surface of the switch arm 64 engaged by the abutment portion 42 may wear down due to the abrasion of the surfaces. It will be noted that the contact pin 62 completes the electrical circuit be tween contacts 56 and 58 through a predetermined degreeof'pivotal movement of the switch arm 64. Thus, even though abrasionof these aforementioned surfaces may eventually result in pivotal movement of the switch arm 64 through a reduced arc, contact pin 62 will nonethless still be able to contact the laterally spaced contacts 56 and 58 and thereby provide a builtin compensation for the wear of these parts. I

Furthermore, it will be noted that the switch housing 44 may be easily removed from the casing 12 by sliding it rearwardly of the casing and out of the slot 46 of the casing 12. A new housing 44 and the switch components found therein may then be easily installed.

Thus it is seen that a combination lock cylinder and key indicating switch assembly is provided having improved reliability and ease of maintenance and replacement.

It is claimed:

1. In a lock assembly having a cylindrical casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the'core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch assembly for indicating the presence of the key in the key slot of the core comprising: wall means on the casing providing a slot, wall means in the core, a recess communicating the slot in the casing to the key slot in the core, a dielectric. housing slidable into the slot and being radially restrained therein by the wall means on the casing, laterally spaced electrical contacts in the switch housing, contact means movably mounted in the housing for movement between normal open position and a closed position wherein the laterally spaced electrical contacts are connected, and an actuating lever pivotally mounted in the recess of the core and being pivotally moved therein upon insertion of the key into the key slot to move the contact means to closed position.

2. In a lock assembly having a casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch assembly for indicating presence of the key in the key slotof the core and comprising: wall means in the casing providing a slot, a switch housing of dielectric material received in the'slot of the casing with the wall means acting to fix the housing in the radial direction and permit longitudinal movement of the housing to remove the housing from the casing, wall means in the core providing a recess extending generally parallel to the key slot and communicating the key slot of the core to the switch housing, first and second upstanding electrical contacts mounted in laterally spaced relation in the switch housing, a contact pin for electrically connecting the first and second electrical contacts to complete an electrical circuit, a switch arm pivotally mounted in the switch housing and carrying the contact pin, spring means biasing the switch arm to carry the contact pin to a normal open position, an actuating leverpivotally mounted in the recess of the case and having a first laterally extending abutment portion exstanding electrical contacts. 

1. In a lock assembly having a cylindrical casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch assembly for indicating the presence of the key in the key slot of the core comprising: wall means on the casing providing a slot, wall means in the core, a recess communicating the slot in the casing to the key slot in the core, a dielectric housing slidable into the slot and being radially restrained therein by the wall means on the casing, laterally spaced electrical contacts in the switch housing, contact means movably mounted in the housing for movement between normal open position and a closed position wherein the laterally spaced electrical contacts are connected, and an actuating lever pivotally mounted in the recess of the core and being pivotally moved therein upon insertion of the key into the key slot to move the contact means to closed position.
 2. In a lock assembly having a casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch assembly for indicating presence of the key in the key slot of the core and comprising: wall means in the casing providing a slot, a switch housing of dielectric material received in the slot of the casing with the wall means acting to fix the housing in the radial direction and permit longitudinal movement of the housing to remove the housing from the casing, wall means in the core providing a recess extending generally parallel to the key slot and communicating the key slot of the core to the switch housing, first and second upstanding electrical contacts mounted in laterally spaced relation in the switch housing, a contact pin for electrically connecting the first and second electrical contacts to complete an electrical circuit, a switch arm pivotally mounted in the switch housing and carrying the contact pin, spring means biasing the switch arm to carry the contact pin to a normal open posiTion, an actuating lever pivotally mounted in the recess of the case and having a first laterally extending abutment portion extending into the outer end of the key slot and a second laterally extending curved abutment portion engageable with the switch arm, spring means biasing the actuating lever to a normal position wherein the first abutment portion thereof extends into and partially obstructs the key slot whereby when the key is inserted into the slot the actuating arm is pivotally moved causing the second abutment portion thereof to engage and move the switch arm and the contact pin carried thereon to electrically connect the laterally spaced upstanding electrical contacts. 